[editor : Christopher Morgan] [publisher : Virginia Londoner, Gordon R Williamson, John E Hayes] #Magazine

#Abstract

It's the operating systems that turn a hunk of hardware into a clever machine. As Robert Tinney's cover drawing depicts, they are the brains behind the brawn of today's computing systems.

This month two articles analyze the most popular operating system, "CP/M: A Family of 8- and 16-Bit Operating Systems," by Gary Kildall, and James Larson's "The Ins and Outs of CP/M." If you can get by the title of Chris Morgan's editorial - "The New 16-Bit Operating Systems, or, the Search for Benutzerfreundlichkeit" - you'll discover what form the operating systems of the future may take. And Robert Greenberg presents what may be the next popular operating system in his article, "The UNIX Operating System and the XENIX Standard Operating Environment."

[author : Chris Morgan] #Edito

Extract : «  Sam Goldwyn, the "G" of MGM, was famous for his inside-out logic. He once said, "A verbal agreement isn't worth the paper it's written on." This month's topic prompted me to coin a "Goldwynism" of my own: "The best time to talk about the future is before it happens."

In one sense 16-bit microcomputers are definitely here, yet in another they are strangers to us. The personal-computer community still lives in an 8-bit world, straining all 8 bits of every word to perform miracles.

But all that can and must change. Opponents of 16-bit systems cite cost and software conversion problems as the two main justifications for staying with 8 bits. Yet, how can software keep pace with the increased demand for more sophisticated graphics, to name only one area, unless we can address more than 64 K bytes of memory? How will we be able to access the staggering amounts of information in future memory banks without an increase in word size? And then there are the exciting new languages like Smalltalk that demand 16 bits for their operation. Simply put, 16 bits is the only way to go. The 16-bit operating system, therefore, becomes a critical link in the computing chain. [...]  »

TABLE OF CONTENTS

A preview of the first small-computer versions of this exciting language.

[author : Harold Nelson] #Logo #Listing #Programming

Extract : «  The imminent release of not one but two versions of the Logo language for personal computers may be one of the most exciting software developments of the year.

The Logo programming language was developed at the Artificial Intelligence Laboratory at MIT (Massachusetts Institute of Technology). According to the Logo Project's originator and driving force, MIT Professor Seymour Papert, "Logo is the name of a philosophy of education in a growing family of computer languages..."

In the same passage, Professor Papert is quick to point out that Logo is not merely a children's language, although since its development over twelve years ago it has always been intended to facilitate discovery learning by young children. In fact, it represents a kind of "Copernican revolution." Rather than the child being programmed by the computer (as with computer-aided instruction), the child learns by teaching the computer — and has a good deal of fun in the process. In the past, this has been the overriding purpose of the Logo Project. However, Professor Papert states: "An example of a powerful use of list structure is the representation of Logo procedures themselves as lists of lists so that Logo procedures can construct, modify, and run other Logo procedures." (Mindstorms: Children, Computers and Powerful Ideas. New York: Basic Books Inc, 1980, page 217.)

Apple Logo and TI Logo are the first versions of this language that are intended for use with personal computers. TI Logo was developed for the Texas Instruments 99/4 computer, while Apple Logo runs on the Apple II or Apple II Plus computer. Each is a descendant of earlier implementations written in LISP and Pascal for larger computers, and this heritage is evident in both versions of the language. [...]  »

The Digitalker integrated circuits from National Semiconductor can easily give your computer a limited spoken vocabulary.

[author : Steve Ciarcia] #Interface #Electronic #Listing #BASIC #Audio #Book

Extract : «  Recently I was at a local electronics store looking at DVMs (digital voltohmmeters). I didn't want to buy one, but, like looking at new cars, I wanted to reestablish the cost-effectiveness of what I already owned.

Most of the meters in the showcase were 3 1/2-digit units with five or more ranges and many ancillary functions. The sales pitch for every one sounded alike.

While not trying to be cute, I stopped the clerk in midsentence and asked if he had any DVMs that "talked." He completely ignored the question. I had to interrupt him twice to get his attention, and even then, he thought I was being difficult.

Eventually, he said that he had no talking DVMs and never expected to see any. Even though I anticipated his answer, I was testing his response to the idea. Considering that we now have talking toys, talking hand-held DVMs shouldn't sound that strange. In fact, such use would be a relatively minor application of synthesized speech. Someday they will be very common.

While I wouldn't consider this salesman a total loss, there are some people who have to go to Missouri to believe the state exists. I trust, however, that you have an open mind to new technology.

Cost-Effective Speech Synthesis

Advances in the production of high-density LSI (large-scale integrated) circuits and new techniques to synthesize speech have reduced the cost of voice-output systems dramatically. Attaching a speech synthesizer to your computer is now as reasonable financially as adding any other peripheral device. [...]  »

A Compucolor II BASIC program effectively simulates a physical system through the solution of a system of linear differential equations.

[author : Randall E Hicks] #Listing #BASIC #Mathematics #Graphics #Book

Extract : «  Many academic disciplines have used computers for modeling biological, physical, economic, and social systems. Modeling complicated systems once was timeconsuming, expensive, and cumbersome. Yet, as computer-related technology advanced, the magnitude of these problems has dwindled, and the potential for less expensive modeling and simulation tasks in all disciplines has increased.

My purpose is to demonstrate how useful microcomputers can be in mathematical simulations. I will introduce you to modeling the behavior of a system by describing it mathematically with a system of time-invariant linear differential equations. I will show how to solve systems of differential equations by two separate numerical methods. As a framework for the simulation tasks, I will use a simple model as an example for you to follow: a hydrologic model of the forested uplands surrounding Okefenokee swamp in Georiga. [...]  »

Accurate, repeatable tine measurements can be made in rapid succession, and logged for later use.

[author : John Gibson] #Electronic #Listing #Assembly #Time

Extract : «  Accurate time measurement is a fundamental requirement of every elementary physics laboratory. Thanks to modern electronics, most laboratories now use digital timing devices that are activated by photocells or microswitches. This is a great improvement over the hand-operated mechanical stop-clocks that were prevalent only a few years ago, but most electronic timers are still unsatisfactory in one important respect: only the most sophisticated (and expensive) are able to rapidly make and record a succession of elapsed-time measurements.

Data acquisition and logging are natural provinces of the microcomputer. Since small microcomputers and microcomputer trainers are now so widely available, it is only natural to try to adapt them for use in a variety of laboratory measurements. This article will show how a very modest microcomputer can be wired and programmed for use as a sophisticated laboratory timer.

First we will examine the system-independent design considerations for a microcomputer-based, two-channel, data-logging, millisecond timer. Then we will build this design on a Heath ET-3400 microprocessor trainer used with the ETA-3400 expansion accessory. [...]  »

An overview of Digital Research's operating systems, including a 16-bit operating system.

[author : Gary Kildall] #OperatingSystem #History

Extract : «  [...] CP/M was, however, completed by MAA in 1974. It included a single-user file system designed to eliminate data loss in all but the most unlikely situations, and used recoverable directory information to determine storage allocation rather than a traditional linked-list organization. The simplicity and reliability of the file system was an important key to the success of CP/M: file access to relatively slow floppy disks was immediate, and disks could be changed without losing files or mixing data records. And because CP/M is a Spartan system, today's increased storage-media transfer rates simply improve overall response. The refinements found in CP/M are based on its simplicity, reliability, and a proper match with limited-resource computers.

By the mid-1970s, CP/M added a new philosophy to operating system design. CP/M had been implemented on several computer systems, each having a different hardware interface. To accommodate these varying hardware environments, CP/M was decomposed into two parts: the invariant disk operating system written in PL/M, and a small variant portion written in assembly language. This separation allowed computer suppliers and end users to adapt their own physical I/O drivers to the standard CP/M product.

Hard-disk technology added yet another factor. CP/M customers required support for disk drives ranging from single 5-inch floppy disks to high-capacity Winchester disk drives. In response, CP/M was totally redesigned in 1979 to become table-driven. All disk-dependent parameters were moved from the invariant disk operating system to tables in the variant portion, to be filled in by the system implementer.

CP/M is now a multifunction program whose exact operation is defined externally through tables and I/O subroutines. The widespread use of CP/M is directly attributed to this generality: CP/M becomes a special-purpose operating system when it is field-programmed to match an operating environment. Through the efforts of system implementers who provide this field-programming, CP/M is used worldwide in close to 200,000 installations with over 3000 different hardware configurations. [...]  »

An inside look at a large-computer operating system implemented for use with microprocessors.

[author : Robert Greenberg] #OperatingSystem #C #History

Extract : «  [...] The UNIX operating system was originally developed at Bell Laboratories by Ken Thompson, an employee engaged in various programming research projects. With access to an abandoned DEC PDP-7 computer that had no software, Thompson decided in 1969 to write a set of programs that would aid him in software research. Over a period of several years, and with the help of fellow researcher Dennis Ritchie, this set of programs evolved into a full operating system. By 1972, it was recoded for the DEC PDP-11 computer in a newly designed high-level language, called C. The system gained recognition within the Labs and their parent company, Western Electric.

Word of the quality of Thompson and Ritchie's UNIX operating system spread rapidly. Universities, in particular, expressed interest in obtaining UNIX, and in 1973, Western Electric agreed to distribute the system to nonprofit organizations and promptly licensed several dozen educational institutions, including Columbia University, the University of Alberta (Canada), The Children's Museum (Boston), Princeton University, and Harvard University. By 1975, UNIX had become sufficiently popular in the academic world to justify the creation of a UNIX users' organization, later called USENIX.

The first public release of the UNIX operating system, labeled version 5, was an unpolished snapshot of a research project that was still evolving. It was replaced in 1975 with version 6, a system that is still operating today at many sites. UNIX continued to evolve, benefitting from the feedback it received from scores of internal and external test sites. [...]  »

Directly access the I/O and disk access functions of the CP/M operating system.

[author : James Larson] #OperatingSystem #Listing #Assembly

Extract : «  CP/M (Control Program for Microprocessors) is the most commonly used 8080/8085/Z80 operating system. CP/M is easy to use and the Digital Research documentation is reasonably thorough and clear, especially by microprocessor-software standards. However, the documentation is lacking in one area: the explanation of I/O (input/output) and disk interfacing. This article will clarify and expand upon the documentation. A summary of the I/O and disk-interface routines, calling sequences, use of return codes, and typical subroutines using these will be presented. The use of file-control blocks (FCBs) and I/O buffers will also be explained. Finally, some details of the CP/M I/O functions and their workings will be presented. [...]  »

A moderate amount of software makes the 10-device circuit into a flexible floppy-disk controller.

[author : Roger Camp and James Nicholson] #Listing #Assembly #Interface #Storage

Extract : «  [...] The software shown in listing 1 provides disk-formatting, reading, writing, and error-recovery functions. The software can be reassembled to allow relocation of program or page zero variables. Various entry points are shown in table 4.

Before using the FD1771 to read and write data within the sectors on the floppy disk, the disk must be formatted to conform to a certain structure. A program (entry point FORMAT) is supplied that formats all 77 tracks of a standard 8-inch disk in a standard IBM-compatible 128-bytes-per-sector arrangement (each track contains 26 sectors). [...]  »

This analog-to-digital converter features six input channels with accuracy of 8 to 10 bits.

[author : Robert Daggit] #Electronic #Encoding

Extract : «  With the addition of an analog-to-digital converter and some simple sensors, a microcomputer can monitor analog voltages, read light levels, sense temperatures, or read the analog output from laboratory instruments. The six-channel A/D (analog-to-digital) converter that I will describe reads positive voltages from 0 to 3 V, with either 8 or 10 bits of accuracy. It interfaces to the computer through an 8-bit bidirectional peripheral port whose I/O (input/output) lines are individually programmable and latched when used as outputs. [...]  »

An 8-bit microcomputer is harnessed to the Herculean task of computing the mathematical constant e to 115,925 places.

[author : Stephen Wozniak] #Listing #Assembly #BASIC #Mathematics

Extract : «  [...] The purpose of this article is to share my experiences in computing the mathematical constant e to 116,000 digits of precision on an Apple II computer. Although this computation has little intrinsic value or use, the experience was stimulating and educational. The problems I was forced to overcome gave me insights that greatly contributed to new floating-point routines. These routines were, in some cases, two to three times as fast as those currently implemented in some of our languages at Apple. Because I wanted to develop my own solutions to the problem, I did not research existing techniques for computing e to great precision. Therefore, my approaches are quite possibly not state-of-the-art.

I first calculated e to 47 K bytes of precision in January 1978. The program ran for 4.5 days, and the binary result was saved on cassette tape. Because I had no way of detecting lost-bit errors on the Apple (16 K-byte dynamic memory circuits were new items back then), a second result, matching the first, was required. Only then would I have enough confidence in the binary result to print it in decimal.

Before I could rerun the 4.5 day program successfully, other projects at Apple, principally the floppy-disk controller, forced me to deposit the project in the bottom drawer. This article, already begun, was postponed along with it. Two years later, in March 1980, I pulled the e project out of the drawer and reran it, obtaining the same results. As usual (for some of us), writing the magazine article consumed more time than that spent meeting the technical challenges. [...]  »

[author : Mark Pelczarski] #Memory #Review

Extract : «  [...] For $320 you can buy a single module that contains 32 K bytes of programmable memory. The unit plugs into the middle memory slot of an Atari 800, and with the 16 K-byte module provided with your system, gives a full 48 K bytes of memory (it will not work with only an 8 K-byte module ahead of it). [...]  »

[author : Stan Miastkowski] #OnlineService #DataManagement #Storage

Extract : «  No matter where we go or what we do, we're inundated with data. Each day magazines, newspapers, books, technical journals, and the broadcast media spew forth an amazing amount of material. One quickly learns that there is no way to possibly digest more than a tiny fraction of this material, and that's why this uncontrollable avalanche of paper and words has been aptly named the "information explosion." Fueling the frustration is the Herculean task of sifting through library-card catalogs and indexes to locate specific documents. It's a difficult and inefficient way to find the information you need. In addition, new problems crop up when you attempt to physically locate the texts you managed to find references to.

A much better method is available — if you have access to a modem (modulator-demodulator) and a terminal (or personal computer with communication software). The Dialog Information Retrieval Service (part of the Lockheed Missile and Space Company, Inc) offers on-line interactive access to literally millions of references and abstracts. With Dialog, you can locate information on any subject you can possibly imagine just by typing in words or phrases describing the topic you're interested in. You can search for references by names or companies, authors or publications, dates, product codes, or patent numbers (to name only a few). By combining terms, the information you come up with can be as narrow or as broad as you want it to be. And, reprints of the articles or papers you've found references to can be ordered directly from your terminal. When speaking of the amount of information available on the Dialog system, the numbers become mind-boggling. Dialog has some 50 billion bytes of information available on-line in some 130 individual data bases. That works out to a rough total of about forty million individual bibliographic abstracts and references (referred to as citations). If all the citations were printed on 8 1/2-by 11-inch paper, the stack would reach higher than the Empire State building.

The newspaper and magazine indexes are among the most popularly oriented data bases — although Dialog also offers a number of specialized data bases for those in education, industry, applied science and technology, and social science and the humanities. Business information and forecasts are also available. Eighteen new data bases were added to the system in 1980, and at least a dozen more will be available by the end of the year. The system is available 110 hours a week in fifty countries, and all data bases are updated regularly. Each day tens of thousands of new citations are added. Also, if you wish to create your own private data bases for use on the system, Dialog provides this service. [...]  »

[author : Keith Carlson and Steve Haber] #Software #Review #Overview #Office

Extract : «  [...] Choosing a word processor is similar to deciding on a microcomputer. Each has special features (see table 1), and none of the products have all the features.

If you want a word processor that performs math operations, the SuperText II program is for you. If you're looking for a word processor that you can modify, and you know only BASIC, then Write-On! should satisfy your requirements. If you already have one of the 80-column cards, perhaps you should choose the EasyWriter Professional version. If you are looking for a workhorse processor that will handle bulk mailings, then the EasyWriter Professional linked with EasyMailer is also for you, although Super-Text may meet this demand, and, with some pushing, Write-On! could meet the lower end of these requirements. Datacope Scribe has some very nice features, and if you only wish to process text and can live without a find-and-replace feature, the processor will fulfill your needs.

About this time, you may be thinking, "This is a typical review that says all the products are great". Possibly this is true, but we speak with some experience as we used all of the processors while preparing this article. Each met our needs, and performed basic text processing in less than an hour.

A few years ago, such power in a small package, and at this price, was only a dream. And even today, some of the larger systems don't have equivalent features.  »

[author : Scott Mitchell] #Game #Review

Extract : «  [...] Startrek 3.5 is a menu-driven program. After each sequence of events, you are returned to a list that has eleven command numbers and one invisible command. From this list, you pick and choose commands as if it were a menu. Commands include control of phasers, photon torpedoes, impulse and warp drives, long- and short-range sensor scans, and alert status. You can display the ship's current status, call up damage control to see what is or isn't functioning, call for repairs, or have the science computer tell you what objects are in your quadrant. The ship's computer command takes you into a subsystem that scans its data base for data on Klingon warships, starbases, class F stars, planets, unexplored areas, etc. The computer obtains this information each time you request a sensor scan. The invisible command saves the game on disk or cassette. [...]  »

[author : Christopher Kern] #Software #Review #Programming

Extract : «  [...] My recommendation is largely a product of my experience with one of the best and least expensive programming language packages I have come across: the C compiler developed by BD Software (by Leor Zolman of Cambridge, Massachusetts). I have been using the BDS C compiler for over a year, and I think many hobbyists who aren't already using a modern, high-level language could easily switch to C from their BASIC interpreter. C, like BASIC, can be learned quickly, but it has resources that BASIC, even in its ingeniously extended forms, can't match. And while the BDS C compiler does not provide as convenient a programming environment as BASIC — no compiled language really can — it comes about as close as possible to eliminating the worst annoyance of many compilers running on microcomputer systems: the long wait between idea and execution as the compiler cranks out an assembly-language file that must itself be compiled (run through an assembler) before the object program can be tested. [...]  »

LISP vs FORTRAN: A Fantasy

We Interrupt This Program...

A Votrax vocabulary

Microcomputers in Education: A Concept-Oriented Approach

#Book

BASIC, A Hands-On Method, Second Edition, Herbert D Peckham. New York: McGraw-Hill 1981; 17.5 by 23.5 cm, 306 pages, softcover, ISBN 0-07-049160-7, $12.95.

BASIC-Pack Statistics Programs for Small Computers, Dennie Van Tassel. Englewood Cliffs NJ: Prentice-Hall, 1981; 21 by 28 cm, 230 pages, softcover, ISBN 0-13-066381-6, $16.95.

Basically Speaking, A Guide to BASIC Programming for the Interact Computer, Micro Video Corporation. Ann Arbor MI: Micro Video Corporation, POB 7357, 1980; 23 by 28 cm, 201 pages, softcover, ISBN-none, $14.95.

Data Structures Using Pascal, Aaron M Tenenbaum and Moshe J Augenstein. Englewood Cliffs NJ: Prentice-Hall, 1981; 18.5 by 24.5 cm, 545 pages, hardcover, ISBN 0-13-196501-8, $23.95.

The 8085 Microprocessor, Fundamentals and Applications (Hands-On), Howard Boyet. New York: MTI Publications, 1980; 18 by 25.5 cm, 420 pages, softcover, ISBN-none, $17.95.

First Course in Data Processing with BASIC, J Daniel Couger and Fred McFadden. Somerset NJ: John Wiley & Sons, 1981; 21.5 by 28 cm, 443 pages, softcover, ISBN 0-471-08046-2, $17.95.

First Course in Data Processing with BASIC, COBOL, FORTRAN, and RPG, J Daniel Couger and Fred McFadden. Somerset NJ: John Wiley & Sons, 1981; 21.5 by 28 cm, 532 pages, softcover, ISBN 0-47105581-6, $20.95.

Fundamentals of Programming in BASIC, Robert C Nickerson. Cambridge MA: Winthrop Publishers, 1981; 17.5 by 23.5 cm, 400 pages, softcover, ISBN 8-87626305-8, $12.95.

Introduction to Computer Operations, Second Edition, W M Fuori; A D'Arco; and L Orilia. Englewood Cliffs NJ: Prentice-Hall, 1981; 18.5 by 24.5 cm, 620 pages, hardcover, ISBN 0-13-480392-2, $19.

Introduction to Computer Data Processing, Third Edition, Wilson T Price. New York: Holt, Rinehart and Winston, 1981; 19 by 24 cm, 577 pages, hardcover, ISBN 0-03-056728-9, $18.95.

Invitation to Pascal, Harry Katzan Jr. Princeton NJ: Petrocelli Books, 1981; 16.5 by 24 cm, 233 pages, hardcover, ISBN 089433-103-5, $17.50.

MA-2 Microcomputer Applications, Volume I, Howard Boyet and Ron Katz. New York: MTI Publications, 1979; 15.5 by 23 cm, 461 pages, softcover, ISBN 0-89704-026-0, $16.

MA-2 Microcomputer Applications, Volume!, same as above, 290 pages, ISBN 0-89704-027-9, $9.

Microprocessor System Debugging, Noordin Ghani and Edward Farrell. Somerset NJ: John Wiley & Sons, 1980; 18.5 by 28.5 cm, 143 pages, softcover, ISBN 0-47127860-2, $43.50.

Microprogrammed Control and Reliable Design of Small Computers, George D Kraft and Wing N Toy. Englewood Cliffs NJ: PrenticeHall, 1981; 16 by 24 cm, 428 pages, hardcover, ISBN 0-13-581140-6, $21.95.

The Pascal Handbook, Jacques Tiberghien. Berkeley CA: Sybex, 1981; 18 by 23 cm, 500 pages, softcover, ISBN 0-89588-053-9, $14.95.

Programming with FORTRAN/WATFOR/WATFIV, David T Basso and Ronald D Schwartz. Cambridge MA: Winthrop Publishers, 1981; 17.5 by 23.5 cm, 407 pages, softcover, ISBN 0- 87626-638-3, $12.95.

Systems Analysis and Management: Structure, Strategy and Design, Donald V Steward. Princeton NJ: Petrocelli Books, 1981; 16.5 by 24 cm, 287 pages, hardcover, ISBN 0-89433-106-X, $25.

TRS-80 Assembly Language, Hubert S Howejr. Englewood Cliffs NJ: PrenticeHall, 1981; 18.5 by 24.5 cm, 186 pages, hardcover, ISBN 0-13-931139-4, $15.95.

Using Microprocessors and Microcomputers: The 6800 Family, J D Greenfield and W C Wray. Somerset NJ: John Wiley & Sons, 1981; 19.5 by 24.5 cm, 460 pages, hardcover, ISBN 0-471-02727-8, $22.95.

Musical Applications of Microprocessors

TEX and METAFONT: New Directions in Typesetting

#Book

Extract : «  Musical Applications of Microprocessors by Hal Chamberlin Hayden Book Company, Inc Rochelle Park, NJ 1980, 661 pages, hardcover $24.95 [...]

TEX and METAFONT: New Directions in Typesetting by Donald E Knuth Digital Press, Bedford, MA 1979 $12.00 [...]  »